Oman’s sultan arrived in Iran on Sunday for a two-day visit and met with President Ebrahim Raisi in a visit expected to focus on regional diplomatic and security issues.

The visit by Sultan Haitham bin Tariq al-Said came two days after Muscat mediated a prisoner swap between Iran and Belgium.

Oman has traditionally been an interlocutor between the West with the IslamicRepublic and has mediated the release of several foreign citizens and dual nationals held hostage by Iran.

On Friday, Oman helped secure the release of a Belgian aid worker, who was arrested in 2022 and sentenced to 40 years in prison and 74 lashes on trumped-up charges including spying, in exchange for Iranian diplomat and intelligence agent Assadollah Assadi sentenced to 20 years in prison for a failed bomb plot in France against exiled opposition group Mujahideen-e Khalq (MEK).

Dozens of foreigners and dual nationals still remain in jail in Iran, most facing espionage and security-related accusations. Rights groups have criticized the arrests as a hostage-taking tactic by Tehran to win concessions from the West.

Iran and Oman on Sunday signed four documents to improve cooperation in various sectors in the fields of e economic, energy and investment as well as free economic zones.

The documents were inked by Iranian ministers of petroleum, economic affairs and finance as well as the secretary-general of the Supreme Council of Free Trade-Industrial and Special Economic Zones and Omani minister of energy, finance and trade.

The visit comes as Iran also faces renewed criticism of its human rights record and its supply of drones for the Russian invasion of Ukraine.